my bike wont go fast anymore!

[Jethro]

These are the things I would check:

1. Make sure the petcock is flowing well. Disconnect all the lines and keep the petcock at the "on" position and suck on the vacumm line. It should flow pretty good, maybe a pint a minute? Make sure that when it is on the "prime" setting it flows just as nice.

2. Check the fuel line. My bike came with 1/4" fuel line, it's supposed to be 5/16". This could cause a problem.

3. Make sure you don't have any leaks at the intake boots. This can feel exactly like fuel starvation. Some people will tell you to spray WD40 at the intake boots. Be warned, this doesn't always work. My bike had two badly cracked boots and the WD40 didn't cause any change in engine RPM's. You'll have to take 'em off and check them by eye.

4. As others have said, perform a plug read at all different RPM's. Your bike may be burning too lean at the high end. You should be able to tell if it's looking that way by 5 or 6k RPM's. Oh, and before you ask (like I did) apparently you can't just rev it in neutral, you have to be running in gear for a few minutes.

[duaneage]

These are the things I would check:

1. Make sure the petcock is flowing well. Disconnect all the lines and keep the petcock at the "on" position and suck on the vacumm line. It should flow pretty good, maybe a pint a minute? Make sure that when it is on the "prime" setting it flows just as nice.

2. Check the fuel line. My bike came with 1/4" fuel line, it's supposed to be 5/16". This could cause a problem.

3. Make sure you don't have any leaks at the intake boots. This can feel exactly like fuel starvation. Some people will tell you to spray WD40 at the intake boots. Be warned, this doesn't always work. My bike had two badly cracked boots and the WD40 didn't cause any change in engine RPM's. You'll have to take 'em off and check them by eye.

4. As others have said, perform a plug read at all different RPM's. Your bike may be burning too lean at the high end. You should be able to tell if it's looking that way by 5 or 6k RPM's. Oh, and before you ask (like I did) apparently you can't just rev it in neutral, you have to be running in gear for a few minutes.

Beware of contamination if you decide to suck on the vacuum line.

The fuel line size is probably not an isue, this happened suddenly and unless he replaced the 5/16 with 1/4 line recently it is probably not the cause. might be a intake boot but if one was bad it should still get up there without too much trouble. All four would most likely not go bad at once.

How about the choke? Is it rally on when you think it is off? A choke that is slightly stuck on will cause similar problems.

[my98xplorer]

These are the things I would check:

1. Make sure the petcock is flowing well. Disconnect all the lines and keep the petcock at the "on" position and suck on the vacumm line. It should flow pretty good, maybe a pint a minute? Make sure that when it is on the "prime" setting it flows just as nice.

2. Check the fuel line. My bike came with 1/4" fuel line, it's supposed to be 5/16". This could cause a problem.

3. Make sure you don't have any leaks at the intake boots. This can feel exactly like fuel starvation. Some people will tell you to spray WD40 at the intake boots. Be warned, this doesn't always work. My bike had two badly cracked boots and the WD40 didn't cause any change in engine RPM's. You'll have to take 'em off and check them by eye.

4. As others have said, perform a plug read at all different RPM's. Your bike may be burning too lean at the high end. You should be able to tell if it's looking that way by 5 or 6k RPM's. Oh, and before you ask (like I did) apparently you can't just rev it in neutral, you have to be running in gear for a few minutes.

Beware of contamination if you decide to suck on the vacuum line.

The fuel line size is probably not an isue, this happened suddenly and unless he replaced the 5/16 with 1/4 line recently it is probably not the cause. might be a intake boot but if one was bad it should still get up there without too much trouble. All four would most likely not go bad at once.

How about the choke? Is it rally on when you think it is off? A choke that is slightly stuck on will cause similar problems.

My choke cable broke some time ago, and it used to idle around 3 grand, which is high i know, but now the idle seems to have gone back down to about 1500 to 2000, ranging on how hot the bike is. I guess i could check that too. Keep the suggestions coming please!!

[KEITH KRAUSE]

My choke cable broke some time ago, and it used to idle around 3 grand, which is high i know, but now the idle seems to have gone back down to about 1500 to 2000, ranging on how hot the bike is. I guess i could check that too. Keep the suggestions coming please!!

Regarding this "high idle when hot".
Is this what your bike has done recently?...Start the bike cold, idles OK, say 1,200 rpm. Once completely warmed up the bike now idles much higher, say 2,000 rpm. You turn down the idle by using the idle adjuster knob. All seems OK for the moment. But the next time you cold start, it won't hold an idle until you turn up the idle adjuster again. Once warmed up, the idle's too high again.
If this has happened, you have an intake leak. Most likely the manifold o-rings (if you have them) or the manifolds or loose clamps. An intake leak can happen anytime, and it only takes one effected cylinder to cause your problem.
If not an intake leak, fuel starvation.

[my98xplorer]

My choke cable broke some time ago, and it used to idle around 3 grand, which is high i know, but now the idle seems to have gone back down to about 1500 to 2000, ranging on how hot the bike is. I guess i could check that too. Keep the suggestions coming please!!

Regarding this "high idle when hot".
Is this what your bike has done recently?...Start the bike cold, idles OK, say 1,200 rpm. Once completely warmed up the bike now idles much higher, say 2,000 rpm. You turn down the idle by using the idle adjuster knob. All seems OK for the moment. But the next time you cold start, it won't hold an idle until you turn up the idle adjuster again. Once warmed up, the idle's too high again.
If this has happened, you have an intake leak. Most likely the manifold o-rings (if you have them) or the manifolds or loose clamps. An intake leak can happen anytime, and it only takes one effected cylinder to cause your problem.
If not an intake leak, fuel starvation.

It has always idles high, its just recently idling lower and its so much nicer. Some other people said to check the intake boot?? Where is that on my bike and what is it?

[snowbeard]

intake boots are between the carbs and the engine.

[Anonymous]

Lack of thrust

hello, one simple thing to check is the voltage at your battery when the bike is running. At idle you should have ~14.5 volts and when you bring up the rpm's they should increase slightly. If for some reason your rectifier or stator are at fault you will experience a drop in voltage when you raise the rpm's. When this happens at higher rpm's you can't keep the candles lit and will experience spark blow out and lack of power. I had this problem with my 81 1000 and a new rectifier cured what ailed it . The use of a volt meter is all you need to do this simple test. Use the kiss approach and you can't go wrong. Cheers

[my98xplorer]

Re: Lack of thrust

hello, one simple thing to check is the voltage at your battery when the bike is running. At idle you should have ~14.5 volts and when you bring up the rpm's they should increase slightly. If for some reason your rectifier or stator are at fault you will experience a drop in voltage when you raise the rpm's. When this happens at higher rpm's you can't keep the candles lit and will experience spark blow out and lack of power. I had this problem with my 81 1000 and a new rectifier cured what ailed it . The use of a volt meter is all you need to do this simple test. Use the kiss approach and you can't go wrong. Cheers

hmmm, i shall try that right now!

[my98xplorer]

Re: Lack of thrust

hello, one simple thing to check is the voltage at your battery when the bike is running. At idle you should have ~14.5 volts and when you bring up the rpm's they should increase slightly. If for some reason your rectifier or stator are at fault you will experience a drop in voltage when you raise the rpm's. When this happens at higher rpm's you can't keep the candles lit and will experience spark blow out and lack of power. I had this problem with my 81 1000 and a new rectifier cured what ailed it . The use of a volt meter is all you need to do this simple test. Use the kiss approach and you can't go wrong. Cheers

hmmm, i shall try that right now!

ok with the bike running i only have about 11.8v, when i rev it up a little it goes to about 11.9. Now i can only rev to about 5,000rpm and the bike just spits and sputters. I can only go like 45mph now. Any ideas??

[earlfor]

Re: Lack of thrust

I'll put it this way. Your bike has two fuel tanks. One holds gas. The other holds electricity. 11.8 volts is an empty tank. Your charging system is not working.

Earl

ok with the bike running i only have about 11.8v, when i rev it up a little it goes to about 11.9. Now i can only rev to about 5,000rpm and the bike just spits and sputters. I can only go like 45mph now. Any ideas??

[duaneage]

Stator Time.

Sad fact is that igniton coils not only have reduced output when the voltage is low, they use as much electricity as the headlight does.

I saw this really neat battery voltage indicator with thermostat and clock that mounts on the cluster, I think I will get it.

[RacingJake]

Just be glad it's not a Harley cause you'll have 3 tanks to worry about... the oil tank :?

[earlfor]

Could be stator. Could be R/R. Could be both. Could be that 24 year old battery needs to be replaced. :-) :-)

Earl

Stator Time.

Sad fact is that igniton coils not only have reduced output when the voltage is low, they use as much electricity as the headlight does.

I saw this really neat battery voltage indicator with thermostat and clock that mounts on the cluster, I think I will get it.

[earlfor]

Once upon a time, I considered buying a Harley, but realized I could never afford that much oil. :-) :-)

Earl

Just be glad it's not a Harley cause you'll have 3 tanks to worry about... the oil tank :?

[duaneage]

Could be stator. Could be R/R. Could be both. Could be that 24 year old battery needs to be replaced. :-) :-)

]

I'll bet either the regulator is toast or the main feed from the regulator has a bad connection and the regulator is not seeing the battery. Check the red lead from the regulator back to the battery and see if it is burnt, disconnected, or something.

Still could be the stator but the RR is cheaper and easier to change.